textproduct: Quad Cities

KEY MESSAGES

- Northwest flow aloft will keep temperatures cooler than normal for the work week. A brief weekend warm-up will be followed by temperatures near normal next week.

- Numerous upper level disturbances in the flow aloft have the potential to bring a daily risk of isolated diurnal showers Wednesday through Friday.

- A more substantial upper level disturbance looks to bring a chance of rain to the area the second half of the weekend.

SHORT TERM /THROUGH TONIGHT/

Issued at 221 AM CDT Tue May 5 2026

Very strong post-frontal forcing will allow a band of elevated showers to persist through sunrise.

The very short term models depicts a second band of elevated rain that develops across Missouri and moves across the southeast half of the area after sunrise. The post-frontal forcing is substantial, but, the sub-cloud layer is extremely dry so there are questions regarding the areal coverage of this band of precipitation.

The ECMWF-AIFS, AIGFS and HREF-PMM show the entire area dry Tuesday and Tuesday night as do a couple of the deterministic model runs. A deeper dive into the models shows north winds all the way up to 5kft AGL. So the 30-40% pops across the southeast half of the area today and into this evening were initially through to be traceable to some of the wetter ensemble members. The pops are probably a result of the current band of elevated rain shifting south. Based on reporting visibilities where it is raining, amounts will be under 0.05" with many areas only seeing a trace.

After midnight tonight dry and chilly conditions will be seen as high pressure builds into the upper Midwest.

LONG TERM /WEDNESDAY THROUGH MONDAY/

Issued at 221 AM CDT Tue May 5 2026

Wednesday through Friday night Assessment...a certainty (>95%) of cooler than normal temperatures. Low (<20%) confidence on rain chances

Northwest flow aloft will dominate the remainder of the work-week with cooler than normal temperatures.

The global models have weak upper level disturbances passing through on a daily basis that have the potential to produce isolated diurnal rain showers if sufficient moisture is available.

The disturbances on Thursday and Friday are stronger than the Wednesday disturbance and thus may have a low to medium (20-40%) probability of producing diurnal showers. Interestingly the various models and their respective ensembles differ on the Wednesday and Thursday disturbances. The net result of this disagreement is that the model consensus keeps Thursday dry with a very low (10-20%) chance of rain on Wednesday.

Where the models are in better agreement is with the Friday disturbance. Here the model consensus has a 15-30% chance of diurnal showers.

The key message during the work week is that although there is a risk of rain, many locations will remain dry and those areas that see rain will have many hours of dry weather.

Saturday Assessment...medium to high (60-80%) confidence of warmer temperatures

The northwest flow briefly becomes more zonal on Saturday allowing temperatures to surge above normal. There is a weak upper level disturbance that will move through the area, but, atmospheric profiles are very dry so the disturbance should announce itself with an increase in clouds.

Saturday night through Sunday night Assessment...high (>80%) confidence of a cool down to near normal temperatures. Low to medium (20-40%) confidence on rain chances.

The various global models have a respectable system progged to move through the Midwest. However, there are differences on timing and track of the system. Depending upon the model solution, the Gulf is either partially open and supplying moisture, or, the moisture is taking the longer track through Mexico.

There appears to be reasonable agreement that the better chances for rain look to be late Saturday night and Sunday morning. Here the model consensus has 30-50% pops. Either side of those times are 20- 30% pops.

The only concern is the system may track further south than currently forecast. Given the strength of the progged upper low over the northern Great Lakes that is a legitimate concern. Interestingly, the ECMWF-AIFS and AIGFS only show rain late Saturday night with Sunday/Sunday night dry.

Monday Assessment...medium to high (60-80%) confidence on near normal temperatures

Starting early next week the western ridge builds slightly allowing the northwest flow t become slighly more amplified. Temperatures will be close to normal, but, there is yet another upper level disturbance progged to move through in the flow aloft. Again, progged atmospheric profiles are quite dry so only an increase in clouds should mark the passage of the disturbance.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1221 AM CDT Tue May 5 2026

Strong post-frontal forcing will allow elevated SHRA and areas of rain across eastern Iowa and northern Illinois through 14z/05. After 14z/05 the probability for SHRA becomes more questionable as the better post-frontal forcing shifts into Missouri and central Illinois.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.